Magazine and staple feed means for stapling machines



May 22, 1956 H. J. SPENCER MAGAZINE AND STAPLE FEED MEANS FOR STAPLING MACHINES 6 Sheets-Sheet 1 Filed July 16, 1952 INVENTOR.

May 22, 1956 H. J. SPENCER 2,746,045

MAGAZINE AND STAPLE FEED MEANS FOR STAPLING MACHINES Filed July 16, 1952 6 Sheets-Sheet 2 I N VEN TOR.

May 22, 1956 H. J. SPENCER MAGAZINE AND STAPLE FEED MEANS FOR STAPLING MACHINES 6 Sheets-Sheet 3 Filed July 16, 1952 (Ittomeg May 22, 1956 H. J. SPENCER MAGAZINE AND STAPLE FEED MEANS FOR STAPLING MACHINES 6 Sheets-Sheet 4 Filed July 16, 1952 fizz/mm jgwm INVENTOR.

May 22, 1956 H, SP CE MAGAZINE AND STAPLE FEED MEANS FOR STAFLING MACHINES Filed July 16, 1952 6 SheetS Shee't 5 IN VENT OR,

4 Half/161% y 1956 H. J. SPENCER 2,746,045

MAGAZINE AND STAPLE FEED MEANS FOR STAPLING MACHINES Filed July 16, 1952 v 6 Sheets-Sheet 6 INVENTOR United States Fatent MAGAZINE AND STAPLE FEED P/EANS FGR STAPLING P/EACI HNES Herman J. Spencer, Pittsburgh, Pa., assignor to International Staple and Machine Company, Herr-in, iii, a corporation of Pennsylvania Application July 16, 1952, Serial No. 299,156 12 Claims. (Cl. 149) This invention relates to fastener applying devices and more particularly to stapling or tacking devices in which staples or like fasteners are fed to an ejector or driving passage and thereupon acted upon by a fastener driver or ejector to carry them from the driving passage into a workpiece and may be considered as an improvement of the type shown in my pending application, Serial No. 124,790, filed November '1, 1949, and issued as U. S. Letters Patent No. 2,617,097 on November 11, 1952.

A variety of fastener devices have been proposed to deliver and apply successive fasteners to a work-piece. All of these devices have, however, been subject to the objections that the staples are difiicult to clear from the device if it becomes jammed and that staples are loaded against the pressure of the feeding device or have parts which must be manually disengaged before the fasteners can be loaded.

I have invented a fastener device which overcomes these and other objections to the fastener devices which are presently available.

An object of the present invention is accordingly to provide a fastener device which can be rapidly cleared of jammed fasteners.

Another object of the invention is to provide means whereby the fastener pusher may be withdrawn from the device and inserted therein with automatic means acting to disengage and engage the pusher to the means used to urge the pusher to feed the fasteners.

A further object of the invention is to provide a positive locking means for locking the gate which closes the delivery end of the fastener delivery means and receives the fasteners therefrom for ejection into the work-piece.

Another object of the invention is to provide a cooperating delivery and guide means and a gate means all of which are positively held in operative positions by a single locking member, the removal of which permits the device I to be opened for the removal of jammed fasteners.

The present invention provides a stapling device comprising a frame, guide means on the frame terminating at one end thereof, delivery means cooperating with said guide means to carry fasteners thereon and deliver them at a point adjacent the termination of said guide means on the frame, said delivery means including pusher means running on the guide means, spring means tending to carry said pusher means toward the delivery end of the guide means and release means disengaging the pusher means from the spring means upon removal of the pusher means from the guide means and engaging the pusher means and spring means upon insertion of the pusher means on the guide means, and driving means for driving the fasteners from the delivery end of the guide means into a workpiece. Preferably the guide means is provided with retaining means over the guide means for retaining fasteners thereon. A pivoted gate means is preferably provided over the delivery end of the guide means receiving the fasteners from the guide means and delivery means and positioning them for the driving means. A locking means slidable in the frameandengaging the gate means tohold it in position on -.the .frame is .also provided. The locking means is preferably spring tensioned and positioned with respect to the gate and the guidemeans that lifting the retaining means releases the gate and .opens the guide means.

While particular details of the invention have'been described above, other details and advantages will .be apparent from the followingdescription and the accompanying drawings in which:

Figure 1 is a side elevation of'the preferred form of the invention.

Figure 2 is a vertical section through the fastener device of Figure 1.

Figure 3 is a section on the line 3-3 of Figure 2.

Figure 4 is a segmental'section on the line 44 in Figure 2.

Figure 5 is a top plan view of a fastener retaining member.

Figure 6 is a side elevation of the fastener retaining member .of Figure 5.

Figure 7 is an .end elevation of the fastener retaining member of Figure 5.

Figure 8 is a side elevation of a modified gate structure of the invention. v

Figure 9 is an isometric view, broken away, of part of the fastener retaining member and the fastener delivery mechanism.

Figure 10 is an isometric view of a latch means used in the invention.

Figure 11 is an isometric view ,of a spring clip used in the invention.

Figure 12 is an isometric view of a fastener pusher as used in the invention.

Figure 13 is an isometric view of a modified form of gate locking member.

Figure 14 is an enlarged top plan view of a segment of the fastener feeding mechanism in position for insertion of the fastener pusher.

Figure 15 is an enlarged top plan view of the segment of feeding mechanism of Figure 14 showing the fastener pusher being inserted therein.

Figure 16 is an enlarged top plan view of the segment of the feeding mechanism of Figure 14 showing the fastener pusher as being disengaged from the spring clip.

Figure 17 is an enlarged top plan view of the segment of feeding mechanism of Figure 14 showing the fastener pusher engaged by the spring clip.

Figure 18 is an enlarged top plan view of the segment of feeding mechanism ,of Figure 14 showing the fastener pusher engaging the fastener for feeding them.

Figure 19 is a section on the line 19-19 of Figure 18.

Figure 20 is a top view of a preferred form of fastener pusher.

Figure 21 is an isometric view of a modified form of fastener gate.

Figure 22 is an isometric view of a modified form of a frame.

Figure 23 is a modified form of a gate locking member.

Figure 24 is an end elevation of a modified form of stapling device showing the spring clip and fastener retaining means.

Figure 25 is a top plan view of a modified form of spring clip and latch means.

Figure 26 is a top plan view of a modified form of fastener pusher for use with the form of spring clip and latch means of Figure 25.

Figure 27 is atop plan view of a segment of the, modified form of Figures 25 and 26 showing the fastener pusher being inserted.

Ffgure 28 is a top plan view of a segment of the modi- 3 fied form of Figures 25 and 26 showing the fastener pusher disengaging the spring clip from the latch means.

Figure 29 is a top plan view of a segment of the modified form. of Figures 25 and 26 showing the spring-clip engaging the fastener pusher to feed fasteners.

Figure '30 is an isometric View of a modified form of spring clip used in Figure24.

- Figure 31 is an isometric view of 'a modified form of fastener pusher.

'Referring now to the drawings there is illustrated a frame member 50 provided with inwardly pressed grooves 51 terminating in pockets- 52.which protrude from the sides of the frame member. A slot 53 transverse to the grooves 51 is provided on each side of the frame member. A gate 54 is pivoted at one end to a shaft 55 whichis held 'in the .side members of the frame 50. The gate 54 is provided with side flanges 56 having lugs 57 formed inwardly therein whose forward edges 58 (viewing Figure 1) are at an angle to the vertical when the gate is in the closed position. A locking member 59 slidable in the slots .53 in the frame has'projecting lugs 60 on either side which engage the lugs 57 on the gate. The projecting lugs 60.have a sloping face 61 which engages the forward edges 58 of the lugs on the gate to hold the gate inlocked position. The locking member is provided with a lug 62 transverse to the plane of the locking member. A spring 63 mou'nted on a shaft 64 presses against the upper surface of the lugs 62 tending to force the locking member downwardly (viewing Figure 1) into engagement with the gate.

A modified form of gate and frame are shown in Figures 8, 21 22 and 23 respectively. .In the modified form the gate is not pivoted to the frame but is held in closed position by the locking member 159and the side flange lugs 157 of the gate entering the grooves 151 and pockets 152 of the framexmembe r. In addition pins 110 are provided to retain the gate 154 in proper position.

The driving mechanism is of the conventional spring loaded type (see Figure 2). The hand lever 72 is pivoted 'on the frame 50 on shaft 55 and when manual pressure is exerted on said hand lever, as is usual in this type of equipment, it rotates the lever 72, resulting in the driving spring .70 being compressed and then, as is usual, the driving spring 70 is suddenly released for the purpose of actuating the driving plunger 67, thus suddenly freeing lever 72 from the resistance encountered during the compression of the driving spring. The lever 72 is usually allowed to travel a short distance after being suddenly freed and'is stopped by a solid stop which jars the hand of the operator of the device. In order to overcome this undesirable effect I have employed a resilient U-shaped shock absorbing member 76 acting between the lever 72 andthe frame 50 of the device for absorbing the shock when the hand lever is stopped.

A magazine base member 78 (Fig. 2) is fixed to the frame transverse to the line of the driving plunger 67. A staple guide 79 (Fig. 19) is fixed to the magazine base member 78 and extends substantially through the entire length of the base. Fasteners 80 (Fig. 1) are fed onto the guide 79 from the end opposite the gate 54, the crown of the fasteners resting upon the top of the guide 79 and the legs of the fasteners eXtendin'g downwardly between the side walls of the magazine base member 78 and the guide 79. The fasteners are held on the guide 79 by a retaining member 81 (Figs. 8, l8 and 19) pivoted on a'pin 81a (see Fig.1) to the end of the magazine base member 78 opposite the gate54.- This retaining member 81 is provided with a slot 82 beginning at the pivot end and extending to a point adjacent the gate 54. A spring cover member 83 (Figs. and 6) overlies the retaining member 81 and is pivoted with it at the end of the magazine base member '78. The spring cover member 83 is provided with a slot 84 which corresponds with the 'slot 82 in the retaining member (see Figs. 5

and 6). A pulley wheel 85 is mounted for rotation on a pin 86 between the spring cover member 83 and the retaining member 81 adjacent the terminus of the slot 82 and 84 therein. A coiled feeder spring 87 is passed around the pulley wheel 85 and fastened to a retainer latch 88 (Figs. 9, 10 and 1419) pivoted on a pin 89 on one side of the slots 82 and 84 and adjacent the open ends thereof. A cam roller 90 is mounted between the spring cover member 83 and the retainer member 81 on the opposite side of the slots 82 and 84 from the retainer latch 88 (see Figs. 3 and 14). The end of the latch 88 has a notch 91 which is forced toward the cam roller 90 by the tension of the spring 87. The opposite end of spring clip 92 (Figs. 9, 11, 14-19) is provided with a runner portion 93 slidably guided in the slot 84 in the spring cover 83 (Figs. 5-7) and has a vertical flange 94 (Fig. 11) which is adapted to be engaged by the notch 91 of the latch 88 (Fig. 10) and is held thereby with the cam of spring clip 92. The cam follower surface 95 (Figs. 9 and 11) of spring clip 92 is resting against the cam roller 90. The feeder spring 87 has its other end secured to the spring clip 92 at a point transversely away from slot 84 in spring cover 83 (Fig. 5) and the pull of spring 87 (Fig. 2) on the spring clip 92 constantly urges the latter to rotate about its runner portion 93 (Fig. 11) and thereby urges the flange 9 of spring clip 92 to move transversely from the side of the latch 88 to the side of the cam roller 90 in slot 84 of spring cover 83 (Figs. 5 and 14). The spring clip 92 is pulled toward the retaining latch 88 by the notched key 98 of the pusher 96. The notched key 98 is now in contact with the vertical flange 94 of the spring clip 92, after which the latter, together with the key 98 of pusher 96 moves between the cam roller 90 and the retainer latch 88 thereby trans versely shifting the notched end 91 of latch 88 away from the cam roller 90 against the tension of spring 87. Continned movement of the parts in this direction brings the cam follower surface 95 of the spring clip 92 into engagement with the cam roller 90 thereby shifting the flange- 94 of the spring clip 92 transversely towards the retaining latch 88 and thereby off of the notched key 98 of the pusher 96 and held by the notch 91 of the retainer latch 88. As the pusher 96 is completely withdrawn from the loading end of the device, the retainer latch 88, while holding the spring clip 92 moves the latter to rest against the cam roller 99 (see Figs. 14 and 16).

A fastener pusher 96, generally of inverted U-shape, is inserted between the magazine base member 78 and the retaining member 81 and engages the staple guide 79 (see Figs. 2, 12 and 19). Extending upwardly the pusher 96 has a vertical flange 97 which projects outwardly from the body of the latterto extend through slots 82 and 84 in the retaining member 81 and the spring cover 83 respectively to provide afinger grip for moving the pusher 96 in and out of the slots 82 and 84. The flange 97 of the pusher 96 is provided with a notched key 98 (Figs. 2, 12, 14 and 15), which when inserted into the device preparatory to rendering the pusher effective to feed the staples, travels in a plane between, the retainer member 81 and the spring cover 83 to contact the spring clip 92 and move the end 94 of the spring clip flange. together with the spring clip retainer latch 88 of the spring clip 92 transversely away from the cam roller 90 compare Figures 14 and 15 as the notched key 98 of the pusher 96 is moved further in fastener feeding direction, from the position shown in Figure 15to that shown in Figure 17, the edge of the notched key 98 of the pusher 96 passes beyond the vertical flange 9.4 of the spring clip 92 and at this point is alongside of, and obstructing movement of the notch 91 of the latch end 88 from moving transversely towards the cam roller 9!) and as previously explained, spring 87 is constantly urging the flange 94. of the spring clip 9 2-to move transversely towards the cam roller 90 and the instant the'notched key 98 of the pusher 96 is moved beyond the vertical flange 94 of the spring clip 92, the flange 94 is quickly moved from its held position on notch 91 of the retainer latch 88 transversely into position behind and into engagement with the notched key 98 of the pusher 96 by the pull of spring 87 on the spring clip 92 (compare Figs. 15 and 17). The moment the flange 94 of spring clip 92 is moved away from the retainer latch 88 into a position behind the notched key 98 of pusher 96, the spring 87 will begin to move the pusher 96 and spring clip 92 in staple feeding direction as shown in Figures 3, 17 and 18.

The mechanism of disengagement is generally shown in Figures 14 through 18 inclusive and is the reverse of the foregoing mechanism of engagement. When the pusher member 96 is withdrawn from the slots 82 and 84 in order to permit reloading, the spring clip 92 is drawn with it until its cam surface 95 engages the cam roller 90 whereupon it is gradually pushed downwardly from the key 98 (see Figures 15 and 16). At the same time the latch 88 is urged outwardly beneath the slot 82 in the path of the spring clip 92 (see Figure 16). As the pusher member is further withdrawn the clip moves out of the key 98 and moves forward against the notch 91 of latch 88 (Fig. 14) where it is held between the notch 91 and the cam roller 90 (see Figure 14).

In the embodiment of the invention illustrated in Figures 1 and 2 and discussed above, the spring 63 which presses on the lug 62 of locking member 59 to hold the latter in engagement with the gate 54 also presses against the spring cover member 83 to hold it and the retainer member 81 in operative position. The lug 62 of the locking member 59 also rests on the top of the spring cover member 83 or adjacent thereto. When it is desired to open the gate 54, as for example when the fasteners become jammed, the spring cover member 83 together with the retainer member 81 are raised against the pressure of spring 63 carrying with it the locking member 59 to release the gate 54 and at the same time make accessible the staple guide 78 (see Figures 1 and 13). The gate locking member 59 may also be provided with finger grips not shown but similar to the finger grips 189 of the embodiment illustrated in Figure 8 and 23 which project out of the slots 53 in the frame so that the locking member 59 may be raised out of engagement with the gate 54 independently of the spring cover 83.

Figures 25 through 29 illustrate a different embodiment of latch and spring clip mechanism wherein a slot 18-; in the spring cover member 183 is provided with a notch 99 (Figures 25-29) into which a vertically projecting flange 100 on the spring clip 101 engages. A pusher member 102 slides in the staple guide 179 against the staples. The pusher member 102 is provided with an upwardly projecting flange 103 projecting through the slots 182 and 184 in the retaining member and the spring cover respectively to provide a finger grip for moving the fastener pusher 102 in the slots. The flange 103 is provided with a pair of lugs 104 and 105 extending transversely toward the notch 99. The rearward lug 105 is provided with an angled edge 106 which engages the flange 100 (Figure 27) on the spring clip 101 as the flange 103 of the pusher member 102 is pushed into the slots 182 and 184 to force the flange 100 of the spring clip 101 out of the notch 99 (Figure 28) into engagement with the lug 104 thereby to permit spring 187 to exert pressure on the pusher member 102 to move the latter towards the gate thereby feeding staples into driving position (see Figures 27, 28 and 29). In this embodiment the feeder spring 187 is attached to the spring clip 101 at a point transversely away from the lug 193 of spring clip 101 and lug 193 is simultaneously slidably held in line in slots 184 of the spring cover 183 so that spring 187 constantly urges the flange 100 of spring clip 101 to move transversely toward the notch 99 of the slot 184 using the lug 193 as the pivot point (see Figures *29). In view of the above description, it will be understood that the flange 100 of the spring clip 101 when pulled away from the end of the gate 154 towards notch 99 by lug 104 of pusher 102 as the latter is withdrawn from the slots 182 and 184 to reload fasteners onto the staple guide 179 is urged by lug 104 into the notch 99 by the pull of spring 187 on the clip, whereupon the pusher member can be completely withdrawn from the slots 182 and 184.

In Figures 24 and there is illustrated a modified spring clip 107 which may be substituted for the spring clip 101 of Figures 25 through 29. In this modification the flange 293 is carried upward over the spring cover 283 to form a finger grip 108 by means of which the spring clip can be drawn back along slots 282 and 284 for reloading and by exerting manual pressure on finger grip 108 the flange 200 of spring clip 107 is thereby urged from lug 204 into notch 199.

While certain preferred embodiments of the invention have been illustrated and described it will be understood that it may be otherwise embodied within the scope of the following claims.

I claim:

1. In a stapling device having a frame and an ejector means carrying a fastener from the device into a work piece, guide means on said frame terminating at one end thereof, delivery means cooperating with said guide means to carry fasteners thereon and deliver them to the ejtector means at a point adjacent the termination of said guide means on the frame, said delivery means including pusher means running on the guide means, spring means adjacent the guide means, a clip fixed to one end of said spring means and releasably connected to the pusher means, said spring and clip tending to carry said pusher means toward the delivery end of the guide means, and release means on the guide means disengaging the pusher means from the clip upon removal of the pusher means from the guide means and engaging the pusher means and clip upon insertion of the pusher means on the guide means.

2. In a stapling device having a frame and an ejector means carrying a fastener from the device into a work piece, guide means on said frame terminating at one end thereof, retaining means over said guide means retaining fasteners thereon, delivery means on said retaining means cooperating with said guide means to carry fasteners thereon and deliver them to the ejector means at a point adjacent the termination of said guide means on the frame, said delivery means including pusher means running on the guide means, spring means adjacent the guide means, a clip fixed to one end of the spring means and releasably connected to the pusher means, said spring and clip tending to carry said pusher means toward the delivery end of the guide means, and release means on the retaining means disengaging the pusher means from the clip upon removal of the pusher means from the guide means and engaging the pusher means and clip upon insertion of the pusher means on the guide means.

3. In a stapling device having a frame, guide means on said frame terminating at one end thereof, delivery means hinged over said guide means and cooperating therewith to deliver fasteners at a point adjacent the termination of the guide means on the frame, said delivery means including a cover member hinged on the guide means, gate means about the delivery end of the guide means and slidably removable therefrom, a pair of slots in the frame covered by the gate means, a pair of corresponding slots in the gate means, and locking means slidable in the slots in the frame to engage the slots in the gate to lock it in position on the frame, said locking means being positioned adjacent to and above the delivery means whereby lifting the cover member on the hinged joint disengages the locking means from the gate.

4: A stapling device as claimed in claim 3 having a spring tending to force the locking means towards engagernent with the gate and cover member and force the delivery means in closed position over the guide means.

5. In a stapling device a frame, a guide bar fixed to and terminating at one end of said frame in a fastener ejection chute, a cover member on said guide bar form- "ing a fastener passage therewith, a fastener pusher movable along said guide bar beneath the cover member, spring means fixed at one end to said cover member, clip means fixed to the opposite end of said spring means and releasably engaging said fastener pusher, means for manually moving said pusher member along the guide bar, means releasing the spring means from the fastener pusher when the fastener pusher is withdrawn from the guide bar, and means on the pusher reengaging the spring means on the fastener pusher when said fastener pusher is inserted onto the guide bar.

6; A stapling device as claimed in claim 5 in which the cover member is provided with a slot extending substantially the entire length thereof and the pusher member has a handle portion extending through said slot for manual withdrawal of the fastener pusher.

7. A stapling device as claimed in claim 5 in which the cover member is provided with a slot extending sub stantially the entire length thereof, a spring retainer means adjacent the end of the device opposite said fastener ejection chute adapted to receive and retain one end of said spring means, said spring means exerting pressure to disengage itself from the pusher means and into engagement with said spring retainer means as said pusher means is withdrawn from the device and means on said pusher means to urge said portion of the spring means from said spring retainer means into engagement with the pusher means when the latter is inserted into the device.

8. A stapling device comprising a frame, a guide bar fixed to and terminating at one end of said frame adjacent a fastener ejector chute, a retaining member on said guide bar forming a fastener passage therewith, a slot extending substantially the entire length of said retaining member and open at the end opposite the termination of the guide bar on the frame member, a cover member over said retaining member and having a slot therein, parallel to and above the slot in the retaining member, fastener pusher member movable along said guide bar beneath the retaining member, handle means on said fastener pusher extending through the slots in the cover member and the retaining member for manual engagement, latch means pivoted between the cover member and retaining member adjacent the open end of the slot on the cover member, cam roller means between the cover and retaining member opposite the latch means, spring means fixed at one end to said latch means tending to force the latch means against the cam roller means, a

spring clip on the opposite end of said spring means slidable in the slot in the cover member and releasably engaging the fastener pusher member, a cam surface on said spring clip, said cam surface extending between the cover member and retaining means a distance such as to impinge against the cam roller as the pusher member is withdrawn from the slots in the cover and retaining means, said spring clip being movable with the pusher member during retraction in the slots until the cam surface impinges against the cam roller and is thereby disengaged from the pusher member and engaged upon the latch means when the fastener pusher is withdrawn from the slot in the cover member, and means on the pusher member engaging said latch means to move it out of engagement with the spring clip when the pusher member is reinserted inthe slot causing the spring means to urge the spring clip from the latch to engagement with the pusher member.

9. A stapling device as claimed in claim 8 in which retaining and cover members at'the'end' of the slot in the cover member adjacent the termination of the 'guide bar on the frame and extends substantially parallel to the two sides of the slot.

10. In a stapling device having fastener feeding means, fastener guide means terminating at afastener ejection chute, delivery means cooperating with said guide means to carry fasteners thereon and deliver them to said ejection chute, said delivery means including fastener pusher means running on said guide means, spring means adjacent the guide means, clip means connected at one end of said spring means and movable over said guide means, said clip means being releasably connected to the pusher member and with the spring means tending to carry said pusher means toward said ejector chute, release means on the guide means adapted to disengage the pusher means from the spring means upon manual removal of said pusher means, and means for engaging the pusher means and spring means upon insertion of the pusher means on the guide means.

11. In a stapling device comprising a frame, a fastener guide bar fixed to and terminating at one end of said frame in a fastener ejection chute, a cover member on said guide bar forming a fastener passage therewith, a fastener pusher member movable along said guide bar beneath said cover member, feeder spring means, clip means connected at one end to said spring means and releasably engaging said fastener pusher member for urging the fastener pusher member towards said ejector chute, means for manually moving said fastener pusher member along said guide bar, means for releasing the spring means from the fastener pusher member when said pusher member is withdrawn from the guide bar, latch means pivoted to the cover member at the end opposite the ejector chute, said latch means being connected to the opposite end of the spring means and receiving the clip means when released from the pusher means, and means for re-engaging the feeder spring on the fastener pusher member when said fastener pusher member is inserted onto the guide bar.

12. A stapling device as claimed in claim 11 wherein cam means are provided on the cover member adjacent the latch means in the path of travel of the clip means, said cam means engaging the clip means to disengage it from the pusher member as the pusher member is withdrawn from the cover member, and engage it upon the latch means.

13. In a stapling device having a frame and an ejector means carrying a fastener from the device in a work piece, a guide means on the frame terminating adjacent the ejector means, and receiving staples thereon, a retainer means over said guide means, a cover means spaced over the retaining means and hinged to the guide means, pusher means movable along the guide means, a handle on said pusher member extending through slots in the retaining member and cover member for manual engagement, latch means pivoted at one side of the slots between the retaining means and cover means remote from the ejector means, cam roller means between the retainer means and cover means adjacent the latch means and on the opposite side of the slots in the retaining means and cover means, pulley means between the cover means and retaining means adjacent the ejector means, spring means fixed at one end to the latch means and biasing said latch means toward the cam roller means, said spring means passing around the pulley, a clip member attached to the opposite end of the spring means and removably engaging the pusher member for to and fro movement therewith, a cam surface on said clip adapted to engage the cam roller as the pusher member is withdrawn from the slots and be simultaneously disengaged from the pusher 9 member and engaged upon the latch means as the pusher member leaves the slots, and means on the pusher member engaging the latch means to simultaneously disengage it from the spring clip and engage it with the pusher member when the pusher member is inserted in the slots.

References Cited in the file of this patent UNITED STATES PATENTS Wampler Sept. 13, 1949 

